Starting from AviSynth v2.5 a fourth color format is available besides RGB24, RGB32 and YUY2: YV12. Starting from this version many filters will also work in YV12. The available (internal) filters are listed here and divided into specific groups, including some information and in which color format these filters work.

You could also see an alphabetical listing of the commands in the AviSynthManual.

Trims a video clip so that it includes only the frames first-frame through last-frame.

RGB24, RGB32, YUY2, YV12

Filters for treating interlaced video

Currently (v2.5x and older versions), AviSynth has no interlaced flag which can be used for interlaced video. There is a fieldbased flag, but contrary to what you might expect, this flag is not related to interlaced video. In fact, all video (progressive or interlaced) is framebased, unless you use AviSynth filters to change that. There are two filters who turn framebased video into fieldbased video: SeparateFields and AssumeFieldBased. More information about fieldbased video can be found here.

Takes pairs of fields from the input video clip and combines them together to produce interlaced frames.

RGB24, RGB32, YUY2, YV12

Audio filters

Prior to v2.5 the audio samples are converted to 16 bits when using one of these audio filters. Starting from v2.5 the audio samples will be automatically converted if any filters requires a special type of sample. This means that most filters will accept several types of input, but if a filter doesn't support the type of sample it is given, it will automatically convert the samples to something it supports. The internal formats supported in each filter is listed in the colorspace column. A specific sample type can be forced by using the ConvertAudio functions.

If the sample type is float, when AviSynth has to output the data, it will be converted to 16 bit, since float cannot be passed as valid AVI data.